The disclosure relates to a semiconductor memory device, and a memory system and a memory controller that are designed to use a memory device with a relaxed timing requirement specification at a low temperature and thus to improve yield of the memory device.
A memory device operates according to timing parameters such as a time to write data to a memory cell, a wordline activation time, and a precharge time. Since the timing parameters have characteristics that times become longer at a low temperature, the timing parameters are regarded as violating a timing requirement specification of the memory device during a test, thereby reducing semiconductor yield. The reduction in the semiconductor yield is expected to be more serious with a tendency to semiconductor microfabrication. Therefore, there is a demand for a method of systematically managing timing parameters according to a temperature.